jailbreak 3g 3.1.2

so i restored my iphone from itunes
and its asking me to insert a valid sim
but i DONT have an at&t sim card
how do i get passed this?
like jailbreaking it ? but how?
ive read this forum and it says i CAN downgrade baseband
so quit telling me i cant!
and i know what jailbreaking and unlocking are.

so i restored my iphone from itunes
and its asking me to insert a valid sim
but i DONT have an at&t sim card
how do i get passed this?
like jailbreaking it ? but how?
ive read this forum and it says i CAN downgrade baseband
so quit telling me i cant!
and i know what jailbreaking and unlocking are.

from your link above:
"Note: This unlocking guide will work for you only if your Modem Firmware (Baseband) version is 04.26.08. If you have upgraded directly to iPhone 3.1.2 stock firmware from iTunes then you are pretty much out of luck for now."

what baseband are you at ? if 05.11.07, your stuck for now because Ultrasnow won't unlock it

if you are at 04.26.08, your in luck! Ultrasnow works with that version

this is what i just did though,
i DFU'ed, left shift restore, and clicked the 3.1.2 custom restore
it just finished.
but it still asks for the valid sim card.
and you see i dont have a at&t sim card.
so is there a way that i can get around this?

this is what i just did though,
i DFU'ed, left shift restore, and clicked the 3.1.2 custom restore
it just finished.
but it still asks for the valid sim card.
and you see i dont have a at&t sim card.
so is there a way that i can get around this?

to check, click on settings -> general -> about, scroll down to "modem firmware"

3.1.2 custom restores made from pwnagetool do not upgrade your baseband allowing you to install the latest firmware 3.1.2 with older unlockable basebands (04.26.08) so that you can use non-official sim cards (non at&t).

if you updated to 3.1.2 via iTunes, then you are stuck unless you put in an official sim card from at&t

if you were on 3.0.1 or 3.0 and then upgraded using the custom 3.1.2, your baseband would have remained unlocked at 04.26.08

and you need a custom firmware that has been activated via pwnage tool

he is at 05.11.07

from Dev-Team's blog:

This release allows your baseband to remain unlocked at 3.1.2, but it does not unlock a new baseband put there by restoring to official 3.1.x. It is super important that people who need the unlock to understand they can keep it only by starting at 3.0 (or earlier) and updating solely to custom IPSWs that don’t update the baseband. For those who have been onboard the “unlock train”, simply install ultrasn0w via Cydia once you’ve restored to your custom IPSW. Don’t forget to turn off the “3G” setting in Settings->General->Network if you use T-Mobile in the U.S.A.

8. For 3G and 3G(S) users who are Pwned, PwnageTool is your key to updating in the future, just remember to never install an update directly from Apple, always use an .ipsw that has been created with PwnageTool.

The 3.1 update for the iPhone 3G and 3GS contains such an update, so running the vanilla updater straight away with iTunes will reprogram and update the baseband.